Device for artificial illumination



Feb. 11, 1930. .L. x. CHAMPEAU 2 DEVICE FOR ARTIFICIAL ILLUMINATIONFiled April 25, 1923 INVENTOR MM By A TTORNE Y 5 Patented Feb. 11, 1930UNITED STATES PATENT OFFICE LAWRENCE CHAMPEAU, OF NEW YORK, N. Y.,ASSIGNOR T0 KIRBY, CHAMPEAU CO., INC., OF NEW YORK, N. Y., A CORPORATIONOF NEW YORK DEVICE FOR ARTIFICIAL ILLU MINATION Application filed April25,

This invention relates to artificial illumi nating devices, and moreparticularly to illuminating devices for use in art galleries.

In the lighting of art galleries it has been the practice to illuminatepaintings hung upon the side walls by means of lights with reflectorslocated slightly above the paintings so as to direct the lightdownwardly at an angle upon the paintings and to prevent the direct'raysfrom striking the eyes of the observer. The upper part of a painting isordinarily produced in colors of comparatively light tones. The methodof illumination just described which has been heretofore employed hasthe disadvantage that the lighter upper part of the painting isilluminated much more brightly and is brought out more clearly andstrongly than the darker lower part, thereby producing an effect quitedifferent from that intended by the artist as when the picture isilluminated by daylight. The reflectors and supporting de vices employedin this method also cast objectionable shadows when the gallery isilluminated by daylight.

One of the principal objects of the present invention is to improve theconstruction and arrangement of illuminating devices for art galleriesand to provide a device so arranged in a gallery that a picture hungupon a wall of the gallery will appear to be substantially uniformlyilluminated by the light directed thereupon.

With this and other objects in view, the invention comprises the noveland improved features, constructions and arrangements of partshereinafter described and particularly pointed out in the claims, theadvantages of which will be readily understood and appreciated by thoseskilled in the art.

The invention will be clearly understood from the accompanying drawingsillustrating the invention in its preferred form, and the followingdetailed description of the constructions therein shown.

In the drawings- Fig. l'is a view in section of an illuminating deviceembodying certain features of the present invention, the section beingtaken substantially along the axis of said device;

1923. Serial No} 634,416.

Fig. 2 is a view of the illuminating device taken in the direction ofthe axis thereof from its forward or lens side;

Fig. 3 is a view in vertical section illustrating an art gallery withilluminating devices arranged therein in accordance with certainfeatures of the present invention; and

Fig. 4 an underside plan view illustrating the ceiling of a gallery witha series of illuminating devices installed to illuminate the side wallsof the gallery.

The illuminating device illustrated in Figs. 1 and 2 of the drawingcomprises a casing indicated at 2, at the rear end of which is mounted adevice indicated at 4 for producing artificial illumination, this devicein the construction shown consisting of an ordinar electric light bulb.Associated with the light bulb 4 is a light collecting reflectorindicated at 6 mounted on the bulb support and surrounding the rearportion of the bulb so as to direct the light rays striking the interiorsurface thereof toward the forward end of the casing 2. This reflectormay be varied in cross section as desired to produce the mostadvantageous results.

Mounted within the forward end of the casing is a light directing andconcentrating lens indicated at 8. This lens, which may be ofrectangular outline as shown in the drawings or of any other suitableoutline, is constructed and arranged to deflect the rays transmittedthereto directly from the source of illumination and also the raysreflected thereupon from the reflector 6 toward the axis of the lens,thereby concentrating the light within a relatively small area. Toproduce this result the lens is preferably formed upon its outer facewith a series of concentric circular prismatic ridges or prisms, asshown in Figs. 1 and 2 Fig. 1 illustrates the manner in which the raysstriking the lens are deflected toward the axis of the lens, the raystransmitted to the lens directly from the source of illumination beingindicated in dotted lines and the rays reflected from the reflector 6upon the lens being indicated in dot-and-dash lines. Vith a lensconstructed with prismatic ridges as shown in Fig. 1, the deflecting ofthe light rays as they pass through the lens is of course due to therefracting action of the glass.

In employing an illuminating device of the character illustrated inFigsQl and 2, the illuminating device is preferably installed in thegallery substantially in the manner shown in Fig. 3. As shown in thisfigure. one or more of the illuminating devices indicated at 10 aremounted in the ceiling of the gallery and are directed obliquely towarda side wall of the gallery. The illuminating devices may be concealed bymeans of a beam 12 secured to the ceiling and an angle plate 14 securedto the beam for supporting the illuminating devices. This figure shows apicture indicated at 19 hung upon the side wall 18 of the gallery. Thepicture is preferably located. upon the side wall or the illuminatingdevice is so directed that the rays from the source of illuminationtransmitted along the axis of the illuminating device or the axis of thelens will strike the picture at a point substantially of the distancefrom the top to the bottom of the picture. The illuminating deviceproduces a prism or cone of light at the central part of which the lightis strongest, the light becoming gradually somewhat dimmer from thecentral axis of the cone toward the margin thereof. This cone of lightis indicated diagrammatically in Fig. 3 by the dotted lines. \Vith theconstruction and arrangement of the illuminating devices illustrated inFig. 3 and the location of the painting or other picture with relationthereto as shown and described. the lower of the picture will be locatednearer the central axis of the light cone than the upper third of thepicture. The upper third of the picture, however, will be located nearerthe source of illumination. The result will be that the picture willreceive a strong, substantially even and uniform illumination over itswhole surface.

Fig. 4 shows a series of illuminating de vices mounted in the ceiling ofa gallery so as to give a substantially uniform illumination from oneend of each of the side and end walls of the gallery to the other. Asshown in this figure, a series of illuminating devices constructed asshown in Figs. 1 and 2 are arranged in abutting relation at a distancefrom the corresponding side and end walls so as to form bands of theseilluminating devices as shown in this figure. Each of the illuminatingdevices in these bands is preferably arranged as shown in Fig. 3 so asto direct the light obliquely at an angle upon the adjacent side walland the illuminating devices are concealed from an observer in thecentral part of the gallery by means of beams 12 and angle plates 14.

With the illuminating devics constructed and arranged as abovedescribed, these devices do not in any way interfere with the properillumination of the gallery by daylight. Not

only do these devices produce a uniform and even lighting etl'ect uponthe paintings or upon the side wall of the gallery, but by means of thedevices associated therewith, shown in Fig. 3, the direct rays from thesource of illumination are prevented flOIl'l striking the eye of theobserver so that there is no interference with the clear view of thepicture. The spaces between the bands of lighting devices themselves andbetween said bands and the walls of the room indicated at 16 in thedrawing, may be filled with glass suitable for the transmission ofsunlight into the gallery. Thus, with this system, the gallery may bearranged for either artificial illumination or daylight illumination.The arrangement of the artificial illuminating devices enables thegallery to be lighted in a. highly cfiicient and satisfactory manner bysunlight. Furthermore, the illuminating means of the present inventionpermits the inconspicuous arrangement of the source of artificialillumination and at the same time its construction lends itself readilyto architectural adaptation,

It is to be understood that the invention is not limited to theparticular construction and arrangement of parts of the illustratedembodiment of the invention, but that the invention may be embodied inother forms within the scope of the claims.

Having explained the nature and object of the invention, and havingspecifically described a construction and arrangement embodying theinvention in its preferred form, what is claimed is 1. Illuminatingdevices comprising, in combination, a source of illumination and a lightdirecting and concentrating lens arranged to produce a symmetricalillumination the axis of which is substantially perpendicular to theaxis of the lens, and located adjacent the ceiling of a gallery andspaced from a side wall so that the axis of illumination is directedobliquely downwardly and outwardly toward the nearer side wall.

2. Illuminating devices comprising, in combination, a source ofillumination, a light directing and concentrating lens arranged toproduce a symmetrical illumination the axis of which is substantiallyperpendicular to the axis of the lens, and located adjacent the ceilingof a gallery and spaced from a side wall so that the axis ofillumination is directed obliquely downwardly and outwardly toward thenearer side Wall, and means for concealing said source of illuminationfrom an observer in the central part of the galler 3X Illuminatingdevices comprising, in combination, a source of illumination, a lightcollecting reflector, and a light directing and concentrating lensarranged to produce a symmetrical illumination the axis of which issubstantially perpendicular to the axis of the lens, and locatedadjacent the ceiling of a gallery and spaced from a side wall so thatthe axis of illumination is directed obliquely 1 downwardly andoutwardly toward the nearer side wall.

4. Illuminating devices comprising, in combination, a source ofillumination and a light directing and concentrating prismatic lensarranged to produce a symmetrical illumination the axis of which issubstantially perpendicular to the axis of the lens, and locatedadjacent the ceiling of a gallery and spaced from a side wall so thatthe axis of illumination is directed obliquely downwardly and outwardlytoward the nearer side wall.

5. Illuminating devices comprising, in combination, a source ofillumination, a light directing and concentrating prismatic lensarranged to produce a symmetrical illumination the axis of which issubstantially perpendicular to the axis of the lens, and locatedadjacent the ceiling of a gallery and spaced from a side wall so thatthe axis of illumination is directed obliquely downwardly and outwardlytoward the nearer side wall, and means for concealing said source ofillumination from an observer in the central part of the gallery.

this 16th day of Signed at New York city April, 1923.

LAWRENCE X. CHAMPEAU.

